The present invention relates to roasted coffee and to a method of roasting coffee.
Numerous roasting processes are known and employed in the roasting of green coffee beans. In conventional roasting, the coffee beans are contacted with hot roasting gas which transfers heat to the coffee beans and increases the temperature of the coffee beans to cause roasting to a desired color. Modifications of conventional roasting processes have been made to accomplish roasting in a relatively short period of several minutes or less. Such "fast roasting" systems have been found to produce an improvement in the amount of water soluble solids extractable from the roasted coffee.
Roasted and ground coffee has been widely sold for many years in the United States and other countries in a "one pound" size can which holds 1,000 cc of the coffee and which yields about 85 cups of coffee. A 1,000 cc quantity of roasted and ground coffee made by grinding coffee beans which have been roasted by a conventional roasting process weighs about 16 ounces. Fast roasting conditions which cause an increase in brew yield have the additional effect of reducing the density of the roasted and ground coffee. The increase in brew yield makes it possible to obtain the same number of cups of coffee from a lower weight of coffee beans, thus providing a potential cost savings both to the manufacturer and the consumer. The decrease in density makes it possible to obtain the same, or approximately the same, number of cups of coffee from a given volume of coffee. This makes it convenient for the consumer to use the less dense coffee since the volume of coffee employed by the consumer in brewing is essentially the same as the consumer had used in brewing conventional roasted coffee.
While the reduced density of fast roast coffee has the advantages mentioned above, conventional roasting is still employed commercially to satisfy consumer demand for coffee having aroma and flavor characteristic of roasted coffee. One of the important characteristics of roasted coffee is the aroma of freshly roasted and ground coffee. As reported at page 211 of the ACS Symposium Services "Thermally Generated Flavor, Maillard, Microwave and Extrusion Processes", Parliment et al., Editors, American Chemical Society, Washington D.C. (1994), methanethiol (or methylmercaptan) is a key compound for the pleasant aroma arising from freshly roasted and ground coffee and its quantification has been suggested as an analytical monitoring process for roasted whole bean freshness.
There is a need for low density coffee which retains the increased brew yield of fast roasted coffee and which has an enhanced package headspace methylmercaptan content.